gmailAutoarchive.js

function gmailAutoarchive() {
  
  var delayDays = 2; // will only impact emails more than 48h old
  var maxDate = new Date();
  maxDate.setDate(maxDate.getDate()-delayDays); // what was the date at that time?

  // Get all the threads labelled 'autoarchive'
  var label = GmailApp.getUserLabelByName("autoarchive");
  var threads = label.getThreads(0, 400);
  
  // we archive all the threads if they're unread AND older than the limit we set in delayDays
  for (var i = 0; i < threads.length; i++) {
    if (threads[i].getLastMessageDate()<maxDate)
    {
      threads[i].moveToArchive();
    }
  }
}

Thank you for the solutions everyone. I had to change older-than to older_than in @blhoward2's solution and it worked perfectly.

function gmailAutoarchive() {
  
  var rules = { // Each label with number of days to keep
    "autoarchive" : 2,
    "newslettersandstuff" : 28
  }

  var batch_size = 100;

  for (let label in rules) {
    
    var keepdays = rules[label];
    Logger.log(`Archiving all threads in ${label} older than ${keepdays} Days`);

    var threads = GmailApp.search(`label:inbox label:${label} older_than:${keepdays}d`);

    Logger.log(`Identified ${threads.length.toString()} threads for archival in ${label}`);

    while (threads.length) {
      var this_batch_size = Math.min(threads.length, batch_size);
      var this_batch = threads.splice(0, this_batch_size);
      GmailApp.markThreadsRead(this_batch);
      GmailApp.moveThreadsToArchive(this_batch);
    }
  }
}

Hey, i am looking to archive all my "read" mails which have "user labels" after 2 days, can anyone help with that?. i want to do it for all mails user labels instead of doing individually for all the labels i have. i also do not want to create a separate label to use as an archived inbox if possible. if not i will go this way

@101legend101 this is my approach, quite simple really. Cheers.

function gmailAutoarchive() {

  // Build the query
  var query = "in:inbox is:read has:userlabels older_than:2d";
  
  // Get the threads
  var threads = GmailApp.search(query);
  
  // Archive the threads
  for (var thread of threads) thread.moveToArchive();

}